The subject matter disclosed herein relates to a screw pump, and more particularly to the lubrication of a multiphase screw pump.
Screw pumps are rotary, positive displacement pumps that use two or more screws to transfer high or low viscosity fluids or fluid mixtures along an axis. A twin screw pump typically has two intermeshing counter-rotating rotor screws. The volumes or cavities between the intermeshing screws and a liner or casing transport a specific volume of fluid in an axial direction around threads of the screws. As the screws rotate, the fluid volumes are transported from an inlet to an outlet of the pump. In some applications, twin screw pumps are used to aid in the extraction of oil and gas from on-shore and subsea wells.
In many cases, a twin screw pump may be used to pump a multiphase fluid from a subsea well, which may be processed to produce petroleum products. Accordingly, twin screw pumps may be configured to prevent the flow of process fluids into the bearings, timing gears, motor, environment, or the like. In particular, twin screw pumps may utilize a shaft seal on each end of each rotor. The shaft seals typically require the usage of a lubricant flush system that maintains the rub surfaces of the sealing system clean and removes heat from the sealing surfaces. In addition, the lubricant flush system may be used to lubricate and cool the bearings and timing gears of the twin screw pump. Such a lubricant flush system may require additional components and maintenance, which adds costs and maintenance to the screw pump system.